Dan, A periodic 100 percent inspection will most accurately and effectively provide the information you are interested in. It need not interfere with production using c=0 inspection which is a proven cost-effective go/no-go screen for operations. Regards, Karl Sauter Sun Microsystems > Date: Wed, 9 Jun 1999 13:59:36 -0700 > From: Dan Brandler <[log in to unmask]> > Subject: Re: [TN] ASSY: Sampling plans > X-To: [log in to unmask] > To: [log in to unmask] > > Although Sampling Plans with zero acceptance numbers are fairly common in the > industry, one of the problems of a zero accept number is that the inspection > log may look like this... > > 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 > 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 > 0,0,0,0,0,0,0,0,0,1 ... (Oh no! A defect!). > > The problem is that there is no warning that the quality is dropping or that > a defect is about to show up. Furthermore, the data, all zeros, provides no > way to estimate confidence limits around the zero percent defective estimate > of the quality of the prior lots. > > Sometimes, an accept number of one is better than zero even though a larger > sample size is required. > > Dan Brandler. > > ################################################################ > TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c > ################################################################ > To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: > To subscribe: SUBSCRIBE TechNet <your full name> > To unsubscribe: SIGNOFF TechNet > ################################################################ > Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. > For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 > ################################################################ > ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################ ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################